Browse Prior Art Database

Nondestructive Diagnostic Memory Test

IP.com Disclosure Number: IPCOM000114670D
Original Publication Date: 1995-Jan-01
Included in the Prior Art Database: 2005-Mar-29
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Hsieh, DM: AUTHOR [+3]

Abstract

A program is disclosed that allows the customer to test system RAM without rebooting the system or disturbing any user application. All memory is saved, tested, and then restored so that a reboot is not necessary after the test has been run. Tests DOS 640k ram, video ram, and VDISK RAM on Simon product.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 88% of the total text.

Nondestructive Diagnostic Memory Test

      A program is disclosed that allows the customer to test system
RAM without rebooting the system or disturbing any user application.
All memory is saved, tested, and then restored so that a reboot is
not necessary after the test has been run.  Tests DOS 640k ram, video
ram, and VDISK RAM on Simon product.

      Many systems have a memory test similar to the one incorporated
in IBM's POST feature.  These tests, however, must be run during boot
up only.  This is because RAM is simply tested, and not saved or
restored.  Since Simon is not a computer, but rather a phone, it
can't simply be turned off and then on.  It's VDISK, unlike most PCs,
is meant to be nonvolatile, and its loss can represent a serious
impact to the user.  The nondestructive memory test allows all system
memory to be tested even under these restrictive circumstances.

      The nondestructive memory test (Nd_Memt) is invoked from a user
interface application using an interrupt call set aside for Simon
services, and a function set aside for the nondestructive memory
test.  When the interrupt is invoked, the VG-230's suspend timeouts
are disabled.  Then a small portion of the present user's stack is
tested.  This is followed by a destructive test to a 32kb buffer area
that is passed for temporary data storage by the caller.  After this,
the main loop stores a block of data into the 32kb temp storage area,
tests the user ram block, and restores...